What is the initial treatment for suspected angle closure glaucoma?

Initial Treatment for Suspected Angle Closure Glaucoma

Patients experiencing acute angle-closure glaucoma should receive immediate medical treatment to lower intraocular pressure (IOP), including aqueous suppressants, parasympathomimetics, and osmotic agents if necessary, followed by laser peripheral iridotomy as definitive treatment. 1

Diagnosis and Clinical Presentation

Acute angle-closure glaucoma (AACC) presents with:

• Pressure-induced corneal edema (blurred vision, halos around lights)
• Mid-dilated pupil
• Conjunctival and episcleral vascular congestion
• Severe eye pain and headache
• Nausea and vomiting
• Rock-hard ocular globe on palpation 1, 2

Initial Medical Management

First-line medications:

1. Aqueous suppressants:

   • Beta-blockers (e.g., timolol)
   • Alpha-2 adrenergic agonists

2. Parasympathomimetics:

   • Pilocarpine (1-2 drops in affected eye, may be repeated up to 3-4 times daily) 3
   • Note: Pilocarpine may be ineffective when IOP is markedly elevated 4

3. Carbonic anhydrase inhibitors:

   • Oral/IV formulations for rapid IOP reduction

4. Hyperosmotic agents (if necessary):

   • For severe cases to rapidly reduce IOP

Definitive Treatment

After initial medical management to lower IOP:

1. Laser peripheral iridotomy (LPI) or surgical iridectomy should be performed as soon as possible 1

   • Creates a bypass channel between posterior and anterior chambers
   • Relieves pupillary block, the key mechanism in most PACD cases

2. Prophylactic LPI in the fellow eye:

   • Should be performed when indicated, as PACD is generally bilateral despite 90% of AACC presenting unilaterally 1

Alternative Approaches for Severe or Refractory Cases

• Argon laser peripheral iridoplasty: Superior to medication alone for controlling IOP in acute primary angle closure 5
• Immediate anterior chamber paracentesis: Effective for rapidly aborting the condition, especially when laser equipment is unavailable 5
• Lens extraction: Emerging as an effective treatment for some patients with primary angle closure and primary angle-closure glaucoma 1, 6

Important Considerations

• Dark-room dynamic gonioscopy should be performed to diagnose PACD and verify improvement in angle configuration following treatment 1
• Delaying definitive treatment should be avoided to prevent permanent damage to the optic nerve 4
• Individuals with heavily pigmented irides may require higher strengths of pilocarpine 3
• During acute phases, miotic agents must also be instilled into the unaffected eye to prevent an attack of angle-closure glaucoma in that eye 3

Follow-up Care

• Monitor IOP and optic nerve status regularly
• Assess for signs of chronic angle damage and glaucomatous optic neuropathy
• Adjust therapy based on clinical response and target IOP (typically 20-25% reduction from baseline) 4

The primary goal of treatment is to quickly decrease IOP to reduce the risk of glaucomatous optic nerve damage while ensuring that progressive angle closure does not occur and the risk of acute angle closure is eliminated 7.